Gabriela,
Coming from a family of attorneys and having once had to take a copyright case to court (successfully), I think you’re on to something with the link you posted. I suggest you pose your question to a qualified intellectual property attorney.
I am relatively new to licensing video work and know that some norms are different than in other fields. I come from a still photography background and have found the discussions here at Creative Cow the most enlightening anywhere on all aspects of video production.
I do know that a creator of intellectual property owns the rights to what they create unless otherwise agreed to contractually (in the U.S. at least). Getting it all in writing, ahead of time, helps deter confusion and bad situations.
Allen